A book to help a DM/campaign judge to quickly generate and populate a fantasy cave/cavern/burrow. It contains tables that can be used to randomly generate attributes such as:
- Cave type, terrain, size, number of entrances
- Features: underground rivers, lakes, vaults, geothermals
- Occupants: number, type, hit dice, abilities
and so on

The majority of the book is comprised of cave layouts that are mapped using Judges Guild's Campaign Hexagon System.

Part of Judges Guild's generic "Universal Fantasy Supplement" line for any fantasy RPG - though clearly targeted at D&D/AD&D.